I run a 1990 100gt Johnson. It has some problems and iI am trying to find out if it worth a rebuild or not. I know that there is at least 1 piston on the right bank that will need to be replaced. It is also over heating on the right side , I think it is due to the water deflecter needs to be changed, the water pumpalso needs to be changed.this motor has got hot several times,is a rebuild a good idea. A shop near me told me I was looking at $1500- $1800. That was going through the powerhead the carbs , awater pump,and having the heads done. Please give some input.